title: Lipooligosaccharide locus class of Campylobacter jejuni: sialylation is not needed for invasive infection.
abstract: Campylobacter jejuni is a highly diverse enteropathogen that is commonly detected worldwide. It can sometimes cause bacteraemia, but the bacterial characteristics facilitating bloodstream infection are not known. A total of 73 C. jejuni isolates, consecutively collected from blood-borne infections during a 10-year period all over Finland and for which detailed clinical information of the patients were available, were included. We screened the isolates by PCR for the lipooligosaccharide (LOS) locus class and for the presence of the putative virulence genes ceuE, ciaB, fucP, and virB11. The isolates were also tested for γ-glutamyl transpeptidase production. The results were analysed with respect to the clinical characteristics of the patients, and the multilocus sequence types (MLSTs) and serum resistance of the isolates. LOS locus classes A, B, and C, which carry genes for sialylation of LOS, were detected in only 23% of the isolates. These isolates were not more resistant to human serum than those with the genes of non-sialylated LOS locus classes, but were significantly more prevalent among patients with underlying diseases (p 0.02). The fucose permease gene fucP was quite uncommon, but was associated with the isolates with the potential to sialylate LOS (p <0.0001). LOS locus classes and some of the putative virulence factors were associated with MLST clonal complexes. Although some of the bacterial characteristics studied here have been suggested to be important for the invasiveness of C. jejuni, they did not explain why the clinical isolates in the present study were able to cause bacteraemia.
authors.affiliation: Department of Medical Sciences, Clinical Bacteriology, Uppsala University, Uppsala, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Ellström
authors.forename: B
authors.initials: B
authors.lastname: Feodoroff
authors.forename: M-L
authors.initials: ML
authors.lastname: Hänninen
authors.forename: H
authors.initials: H
authors.lastname: Rautelin
mesh_terms: D016470:Bacteremia / Q000382:microbiology*; D001770:Blood Bactericidal Activity; D002169:Campylobacter Infections / Q000382:microbiology*; D016123:Campylobacter jejuni / Q000145:classification / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D015331:Cohort Studies; D005260:Female; D005387:Finland; D006801:Humans; D008070:Lipopolysaccharides / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D037521:Virulence Factors / Q000235:genetics*; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; D037521:Virulence Factors; C023023:lipid-linked oligosaccharides; D005723:gamma-Glutamyltransferase
keywords: Bacteraemia; Campylobacter; MLST; blood; infection; invasive; lipooligosaccharide; serum resistance